Grounding system for light oil loading stations



Feb. 20, 1962 Filed April 6, 1959 FIG! J. E. GALLAGHER 3,021,867

GROUNDING SYSTEM FOR LIGHT OIL LOADING STATIONS 5 Sheets-Sheet 1INVENTOR. James E. Gallagher BYWIWZ7GZMM.

ATTORNEY Feb. 20, 1962 J. E. GALLAGHER 3,021,867

GROUNDING SYSTEM FOR LIGHT OIL LOADING STATIONS Filed April 6, 1959 3Sheets-Sheet 2 Feb. 20, 1962 J. E. GALLAGHER 3,021,867

GROUNDING SYSTEM FOR LIGHT OIL LOADING STATIONS Filed April 6, 1959 3Sheets-Sheet 5 FIG.4

INVENTOR. James E. Gallagh r ATTORNEYS ilnited rates Eatehtfi Maine 7Filed Apr. 6, 1959, Ser. No. Sii4,359

1 Claim. (i. 137'565) My invention relates to the loading of light oiltrucks and, more particularly, to assuring that such loading takes placeonly after and while the trucks to be loaded are properly grounded.

It is well-known that a serious hazard exists when a truck which isimproperly grounded is loaded with a light oil such as kerosene.Improper grounding can be masked by such things as a defective groundingclamp, a faulty cable or a high resistance contact with the metal of thetruck due to paint or other insulating media. In addition, it ispossible for the operator to overlook entirely the grounding of thetruck or to overlook the breaking of the grounding connection during theloading process by, for instance, the inadvertent removal of the clampsby which the truck is grounded.

It is the object of my invention to provide light oil loading stationracks with'meansfor properly grounding the trucks to be loaded and withmeans of preventing the transfer of such light oils, whether by pumpingor by gravity or both, from the racks to the trucks if such grounding isor becomes imperfect. Light oil is here defined as a hydrocarbon liquidhaving a gravity above 25.0 AP Oils falling in this category includedomestic fuel oils, naphthas, solvents, kerosene, gasoline andaromatics.

These and other obiects are accomplished by my grounding system whichincludes, in combination with a light oil loading line pump, a generallyhorizontally disposed li ht oil loading rack armassembly, an electronicgrounding detecting device and a hydraulic locking device for theloading rack arm assembly.- The electronic grounding detecting means,e.g., a commercially available Nelson Grounding Indicator, operates anenergizing relay the contacts of which are interposed in the electricalcircuit of the motor driving the loading rack pump. So long as a propergrounding is signaled by the detector, the loading rack-pump can bestarted-or can continue to startingof the pump or the continuance of itsoperation and, therefore, the delivery of oil to the loading-rack by itspump. The hydraulic locking device for the loading arm assembly includesa locking bar for preventing the movement downward of the verticallyswivelling portion of the loading arm assembly, i.e., that portionhereinafter to be termed the loading rack spout, into the load- -drivenpiston and is released by a countervailing hydraulic pressure againstthe piston head. The piston head, then, is disposed between the fluidinlet means and the spring. The hydraulic'pressure in the cylinder isdrawn with the oil from the loading arm assembly via the fluid inletmeans and such pressure, e.g., about 50 pounds, is available in theloading rack assembly only when the pump is operating and forcing oilinto it.

For a more complete understanding of the practical appl cation of thefeaturesand principles-of my invenoperate. If it is "not signaled, therelay prohibits the 3,021,857 Patented Feb. .20, 1962 2 tion, referenceis made to the appended drawings in which:

FIGURE 1 is a side elevation'of alight oil loading rack and a grounding,system in accordance with my invention;

FIGURE 2 is an isometric elevation of'a loadingirack arm assemblyvertical swivel in. cooperation with the hydraulic locking device of thesystem of my invention;

FIGURE 3 is an isometric elevation of the hydraulic locking device ofthe system of my invention; and,

FIGURE 4 is the circuit diagram of electronic elements of the system ofmy invention'in' simplified form.

FIGURE 1 shows a loading rack which includes oil loading line 1 runningfrom loading line pump 2 to the horizontally extending loading armassembly. The air eliminators, strainers and metering devicesnormallypres ent in such an oil line are notshown. Neither are the storage tanksfrom which electric motor-driven pump 2 draws the oil. Supporting column3 holding loading line 1 upright at and by means of bracket 4 is,on'the' other hand, shown in FIGURE 1, as'are'various elements of thesystem of my invention. These elements include the electronic groundingdetector 5 afiixed to column 3;' the grounding detector signal light 6;the truck 7 to be loaded through loading hatch Spgrounding leads 9a and9b and clamp 1i) connecting truck 7 to ground "lead 11 and ground 12 viagrounding detector 5; external stop, start and overload control unit 13and, controlunit lines L L L 15a, and 15b connecting g'roundingdetectorsand the motor of-loadin'g' line pump 2 via control unit 13 Thehorizontally disposed loading arm assembly of the loading rack is showninFIGURE 1 and this assembly includes horizontally swivelling pipeconnecting joint 16 which connects loading line 1 to the downwardlyextending arm of T-shaped pipe section 17. It also includes plug 18.which closes off the upwardly extending arm of pipe section 17 andfurnishes a base for the journal means 19 mounted thereon. 'Iournal'means 19 is, in turn, held in bearing means 2%) mounted on supportcolumn 3 of .theloading rack. Thus, horizontally swivelling pipeconnecting joint 16, journal means 19 and bearing means 2! enable therotation of pipe section 17 about the axial line formed by itsarms'an'd, in the depicted instance, for better than.270.. YThe legofpipe ,section .17, of course,v extends radially ,from such axis.

Further, the loading arm assembly of FIGURE 1 in,- cludes a braceill-which runs between and is connected to flanges on the upwardlyextending arm and the horizontally extending leg ofT-shap'edpipe-section v17. Next in the loading armassembly are pipeconnecting elbow joint 23, a second horizontally swivelling pipeconnecting joint 24, pipe connecting elbow joint 25 and pipe section 26,all of which conduct the light oils pumped from loading line 1 by way ofpipe section 17. This fluid connection thereafter continues by means ofvertically swivelling pipe connecting joint 27, the first half 27a of.which is visible, and the other parts of what I have termed the loadingrack spout, i.e., pipe'section. 28 connected to the second half 27b (seeFIGURE .2) of pipe connecting joint 27, loading valve 29 connected topipe section 28, pipe section 30 connected to loading valve 29, andloading nozzle 31 with a deflector T connected to pipe section 30. Asshown in FIGURE 1, the loading spout is in its normal verticallyinclined position.

As shown in FIGURES 1 and 2, the loading arm as.- sembly includesparts-by 'which'the vertical movement of the loading rack spout atvertically swivelling pipe counectingjoint 27 is partially governed.Among these parts are chains 33 and 34 emanating from so-called loader32, e.g., a commercially available OllCO Springmatic #462 Long RangeLoader, and bumper arm 35 i mounted on loader 32 and impinging uponsecond half 27b of vertically swivelling pipe joint ing rack spout isout of use and elevated. Other parts are grooved adjustable chain leverarm 36 and grooved adjustable chain lever arm 37 mounted on second half27b of vertically swivelling pipe joint 27 and connected to chains 33and 34, respectively.

FIGURES 1 and 2 show, further, the hydraulic locking device for theloading rack arm assembly of the grounding system of my invention. InFIGURE 1, visible parts of the device include swivel locking piston rod38 (shown in locking position), piston cylinder 39, and oil tube 40.Piston cylinder 39 is mounted on pipe section 28 with which it is placedin fluid connection by oil, tube 40. In another embodiment of myinvention,

however, piston cylinder 39 can be mounted on the loader side ofvertically swivelling pipe connecting joint 27, rather than as hereshown, i.e., on the loading rack spout side.

The vertically swivelling pipe connecting joint 27 of the loading armassembly and the hydraulic locking device for the loading arm assemblyof my grounding systern are shown more clearly in FIGURES 2 and 3. InFIGURE 2, the vertically swivelling pipe connecting joint 27 is in anunlocked position (in contrast with FIGURE 1),' Le, in the position ofdelivering oil to the loading rack spout as it is pumped through pipesection 2s. This means that there is no contact between bumper arm 35 27when the loadand the second half 27b of pipe connecting joint 27 asthere is in FIGURE 1 where the loading rack spout is depicted as not inuse and in a vertically inclined position. However, the downwardmovement in vertically swivelling pipe connecting joint 27 isrestrained. Thus, when the loading rack spout made up the second half27b of pipe joint 27, pipe section 28, etc., is depressed by theoperator, grooved adjustable chain lever arms 36 and 37 which arerigidly affixed to the casting that is the second half 27b also rotatedownwardly about. the center line of pipe joint 27 and the coincidingcenter line of journal means 41 mounted on the casting that is the firsthalf 27a of pipe joint 27. But this downward rotation is resisted by thetension in chains 33 and 34 which are connected to grooved adjustablechain lever arms 36 and 37, respectively, and this tension is created bysprings or the like in the two cylinders of loader 32. Indeed, were theoperator not depressing the loading rack spout, this tension wouldincline such spout vertically as is shown in FIGURE 1, unless, ofcourse, counterbalancing was employed to hold the spout in any givenposition.

Further, with respect to the hydraulic locking device for the loadingarm assembly shown in FIGURE 2, locking piston rod 38 is shown in theopen position. This means that locking bar 38 is sufliciently retractedinto piston cylinder 39 so that its end 38a cannot be received in thelock 42 of cam 43 mounted on the original castlug-web of first half 27aof pipe join 27, and so that the loading rack spout can be depressed bythe hand of the operator. Also shown in FIGURE 2 are piston cylinder 39mounted to pipe section 28 by flat plate c4 and U-bolts 45, 46, 47 and48 and oiltube 40 fiuidlylinking piston cylinder39 and pipe section 28.

FiGURE 3 shows-the various parts of one of the embodiments of thehydraulic locking device for a loadand iv, is mounted inside anexplosion-proof housing 60. i

The ground detecting unit 61 is also mounted in housing 60. Points i,ii, iii and iv are, as shown in FIGURE 4, connected to contacts actuatedby relays 62 and 63 which are integral parts of grounding detector 61.

FIGURE 4 also shows lines 64 and 65 and coil 66 in line 64 and withingrounding detector 61. These components, together with truck groundingleads 9a and 9b, clamp 10, ground lead 11 and ground 12, go to make upthe ground circuit which ground detecting unit d1 oversees. The. dots atthe ends of lines 64 and 65 and in the rest of this circuit representconnection terminals. Wire seal points which are necessary to preventvapor leakage into housing 69 are symbolized by at the points wherelines 64 and 65 enter and leave housing 60. In addition, FIGURE 4 shows0.039 segment 67 transformer-coupled with coil 66. Segment 67, anelectrical bridge component, controls the electrical actuation of relays62 and 63. Again, FIGURE 4 shows external stop, start, and overloadcontrol unit 13. In this unit relay contacts M M M and M are inserted inthe starting circuit and motor power lines L L 'and L and the relays areacuated by high impedance relay coil M. v

The system of my invention involves the interaction and cooperation ofitsthree primary parts. When the loading rack operator attachesgrounding clamp Ii to truck-7 as shown in FIGURE 1 and wires 64 and 65of FIGURE 4 are connected, coil 66 of grounding detector 61 isefiectively short-circuited and segment 67, in turn, energizes twocircuits by means of relays 62. and es. The first of these circuitsisthat of signal light 5 which takes the following path: from point Zwhich is connected to the volt, 60 cycle power supply to point i,through the contacts of relay 62 to point ii, through signal light 6 toX which is also connected to the power supply. Similarly the relay 63contacts lying between point iii and point iv are closed when truck 7 isproperly grounded and the 440 volt, 3 phase electrical supply isconnected to the motor of pump 2, albeit by means of the external stop,start and overload control unit 13. in other words, after the groundingcircuit is satisfied and the start switch is closed, a flow of currentis established through the high impedance relay coil M and this closesthe contacts of relays M M M and M in lines L L and L respectively. CoilM then maintains the circuit until it is opened either by means of thestop switch, the overload action or the grounding detecting relayaction. (But, if the grounding has not been properly effected by theloading rack operator, it is clear that the signal light cannot operateand the pump cannot be operated. Further, if improper groundingconditions develop once the pump has started, the light will go out andthe relay 63 contacts lying between point iii and point iv will open tohalt the flow of current to coil M and, as a result, the contacts ofrelays M M M and M will open to stop the pump motor.) Pump 2 thereuponforces oil up loading line 1 to the loading arm assembly. However, thefact that pump 2 is running-does not by itself make it possible for theoperator to load truck 7 for two reasons. The operator must first beable to lower the loading arm assembly into thehatch 8 of truck 7 andthen he must open loading valve 29 which, presumably, was previouslyclosed to avoid oil spillage from loading nozzle 31. And the only waythat the operator can lower the loading arm assembly is to allow pump '2to build up a suflicient hydraulic pressure, e.g., 50 pounds, in theloading arm assembly and, more especially, in pipe section 28 thereof,so that the oil flowing through oil tube 49 from pipe section 28 intopiston cylinder 39 will push against cup gasket 52 and helical spring55, thereby retracting locking bar 38 into the cylinder and out of lock42 of cam 43. In other words, then, the operator cannot load truck '7until grounding detector 5 allows-pump 2 to start and until the runningpump 2 at'the behest 'of grounding detector 5 effects the opening ofmyhydraulic-locking device and makes possible the lowering of theloading rack arm assembly spout.

What is claimed is:

In a light oil loading station rack including an oil loading line, anoil loading ine pump and an electric motor driving the pump, a systemfor preventing the transfer of the oil to a truck to be loaded untilthere is established a proper electrical connection between the truckand a ground, the system comprising an electrical connecting meansbetween the truck and the ground, an electronic grounding detectingmeans, energizing means between the electronic grounding detecting meansand the electric motor driving the pump, a generally horizontallydisposed loading rack arm assembly including a normally verticallyinclined loading rack spout and a pipe connecting means connecting theoil loading line and the loading rack arm assembly and a vertically-swivelling pipe connecting means connecting the loading rack spout tothe remainder of the loading rack arm assembly, a receiving meanspositioned on the vertically swivelling pipe connecting means to receivea piston rod which locks the loading rack spout in the normally ver-"tically inclined position, a piston cylinder positioned on the loadingrack arm assembly having fluid inlet means and containing the pistonrod, compressible spring means for holding the piston rod in thereceiving means, piston head means connected to the piston rod anddisposed *and the electric motor driving the pump, the pump draws theoil from the oil loading line into the loading rack arm assembly and thefluid connecting means between the loading rack arm assembly and thefluid inlet means of the piston cylinder, the oil in the piston cylindercompresses the compressible spring means, the piston rod is withdrawnfrom the receiving means, and the loading rack spout in the normallyvertically inclined position is unlocked.

References Cited in the file of this patent UNITED STATES PATENTS2,649,109 Samiran Aug. 18, 1953 2,703,096 Overbeke et al Mar. 1, 19552,716,999 Badger et al. Sept. 6, 1955 2,727,534 Briede Dec. 20, 19552,802,492 Gosselin Aug. 13, 1957

